import time
incomplete_sign = 50 #.的数量
print('='*23+'开始下载'+'='*25)
for i in range(incomplete_sign + 1):
    completed = "*" * i #表示已完成
    incomplete = "." * (incomplete_sign - i) #表示未完成
    percentage = (i / incomplete_sign) *100 #百分比
    print("\r{: .0f}%[{}{}]". format( percentage, completed,
incomplete), end="")
    time. sleep(0.5)
print("\n" + '='*23+' 下载完成'+'='*25)